<html>
  <?php echo("Hello,   world!");
    echo(" Hello, \"world!\" ");
    echo("'hello'");
    echo('hello');
    echo('');
    echo("");
    echo('\'');
    echo("\'\"");
    echo(' ');
    echo(" ");
    echo("<?php    ?>");
    echo('<?php    ?>');
    echo "a
        multi line string
         should keep formatting"; ?>
  <body>
    <h1>Hello, world!</h1>
  </body>
</html>